hopefully the critters will be in bags seperate from everything else.
once you get home i would put all of the critters in a nice warm space. if packed well they will be fine for a day in the bags.
make several gallons of fresh NSW. use some for the tank the other as a swish bucket for the LR.
get your plumbing figured out.
start setting up the tank. take your time. rushing just makes it take longer. the critters will be fine in the bags. put the sand in. start putting the LR in. swish the LR in the bucket with the freshly made NSW. this will help get off any detritus that is on the LR. gives you a better start on the tank.
start putting water in the tank. use as much water as you can from the old tank. make sure to put some in the sump to prime the pumps. finish filling the tank with NSW. start the tank up. hopefully the temp is not super low. let the tank run for at least an hour before checking and adjusting the salinity. have the heater on in the tank so that it will warm up.
start getting the salinity correct. you might need to test one of the critter bags for temp and salinity. when the temps match than put the critter bags in the tank. you may need to remove some water. let the tank finish getting up to full temp with the fish in the bags. once tank reaches correct temp. for most people it is around 78 degrees, wait another hour for the bags to equalize up to that temp also.
triple check the salinity between a bagged critter and the tank. if the same than release the critters.
this is basically what i would do. not sure exactly what you have around the house for buckets so can not give you exact instructions.
G~
